xref: /freebsd/sys/compat/lindebugfs/lindebugfs.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2016-2018, Matthew Macy <mmacy@freebsd.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/queue.h>
35 #include <sys/blist.h>
36 #include <sys/conf.h>
37 #include <sys/exec.h>
38 #include <sys/filedesc.h>
39 #include <sys/kernel.h>
40 #include <sys/linker.h>
41 #include <sys/malloc.h>
42 #include <sys/mount.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/resourcevar.h>
46 #include <sys/sbuf.h>
47 #include <sys/smp.h>
48 #include <sys/socket.h>
49 #include <sys/vnode.h>
50 #include <sys/bus.h>
51 #include <sys/pciio.h>
52 
53 #include <dev/pci/pcivar.h>
54 #include <dev/pci/pcireg.h>
55 
56 #include <net/if.h>
57 
58 #include <vm/vm.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_map.h>
61 #include <vm/vm_param.h>
62 #include <vm/vm_object.h>
63 #include <vm/swap_pager.h>
64 
65 #include <machine/bus.h>
66 
67 #include <compat/linux/linux_ioctl.h>
68 #include <compat/linux/linux_mib.h>
69 #include <compat/linux/linux_util.h>
70 #include <fs/pseudofs/pseudofs.h>
71 
72 #include <linux/debugfs.h>
73 #include <linux/seq_file.h>
74 #include <linux/compat.h>
75 
76 MALLOC_DEFINE(M_DFSINT, "debugfsint", "Linux debugfs internal");
77 
78 static struct pfs_node *debugfs_root;
79 
80 #define DM_SYMLINK 0x1
81 #define DM_DIR 0x2
82 #define DM_FILE 0x3
83 
84 struct dentry_meta {
85 	struct dentry dm_dnode;
86 	const struct file_operations *dm_fops;
87 	void *dm_data;
88 	umode_t dm_mode;
89 	int dm_type;
90 };
91 
92 static int
93 debugfs_attr(PFS_ATTR_ARGS)
94 {
95 	struct dentry_meta *dm;
96 
97 	dm = pn->pn_data;
98 
99 	vap->va_mode = dm->dm_mode;
100 	return (0);
101 }
102 
103 static int
104 debugfs_destroy(PFS_DESTROY_ARGS)
105 {
106 	struct dentry_meta *dm;
107 
108 	dm = pn->pn_data;
109 	if (dm->dm_type == DM_SYMLINK)
110 		free(dm->dm_data, M_DFSINT);
111 
112 	free(dm, M_DFSINT);
113 	return (0);
114 }
115 
116 static int
117 debugfs_fill(PFS_FILL_ARGS)
118 {
119 	struct dentry_meta *d;
120 	struct linux_file lf;
121 	struct seq_file *sf;
122 	struct vnode vn;
123 	void *buf;
124 	int rc;
125 	size_t len;
126 	off_t off;
127 
128 	d = pn->pn_data;
129 
130 	if ((rc = linux_set_current_flags(curthread, M_NOWAIT)))
131 		return (rc);
132 	vn.v_data = d->dm_data;
133 	buf = uio->uio_iov[0].iov_base;
134 	len = min(uio->uio_iov[0].iov_len, uio->uio_resid);
135 	off = 0;
136 	lf.private_data = NULL;
137 	rc = d->dm_fops->open(&vn, &lf);
138 	if (rc < 0) {
139 #ifdef INVARIANTS
140 		printf("%s:%d open failed with %d\n", __FUNCTION__, __LINE__, rc);
141 #endif
142 		return (-rc);
143 	}
144 	sf = lf.private_data;
145 	sf->buf = sb;
146 	if (uio->uio_rw == UIO_READ) {
147 		if (d->dm_fops->read)
148 			rc = d->dm_fops->read(&lf, NULL, len, &off);
149 		else
150 			rc = ENODEV;
151 	} else {
152 		if (d->dm_fops->write)
153 			rc = d->dm_fops->write(&lf, buf, len, &off);
154 		else
155 			rc = ENODEV;
156 	}
157 	if (d->dm_fops->release)
158 		d->dm_fops->release(&vn, &lf);
159 	else
160 		single_release(&vn, &lf);
161 
162 	if (rc < 0) {
163 #ifdef INVARIANTS
164 		printf("%s:%d read/write failed with %d\n", __FUNCTION__, __LINE__, rc);
165 #endif
166 		return (-rc);
167 	}
168 	return (0);
169 }
170 
171 static int
172 debugfs_fill_data(PFS_FILL_ARGS)
173 {
174 	struct dentry_meta *dm;
175 
176 	dm = pn->pn_data;
177 	sbuf_printf(sb, "%s", (char *)dm->dm_data);
178 	return (0);
179 }
180 
181 struct dentry *
182 debugfs_create_file(const char *name, umode_t mode,
183 		    struct dentry *parent, void *data,
184 		    const struct file_operations *fops)
185 {
186 	struct dentry_meta *dm;
187 	struct dentry *dnode;
188 	struct pfs_node *pnode;
189 	int flags;
190 
191 	dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
192 	if (dm == NULL)
193 		return (NULL);
194 	dnode = &dm->dm_dnode;
195 	dm->dm_fops = fops;
196 	dm->dm_data = data;
197 	dm->dm_mode = mode;
198 	dm->dm_type = DM_FILE;
199 	if (parent != NULL)
200 		pnode = parent->d_pfs_node;
201 	else
202 		pnode = debugfs_root;
203 
204 	flags = fops->write ? PFS_RDWR : PFS_RD;
205 	dnode->d_pfs_node = pfs_create_file(pnode, name, debugfs_fill,
206 	    debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT);
207 	if (dnode->d_pfs_node == NULL) {
208 		free(dm, M_DFSINT);
209 		return (NULL);
210 	}
211 	dnode->d_pfs_node->pn_data = dm;
212 
213 	return (dnode);
214 }
215 
216 struct dentry *
217 debugfs_create_dir(const char *name, struct dentry *parent)
218 {
219 	struct dentry_meta *dm;
220 	struct dentry *dnode;
221 	struct pfs_node *pnode;
222 
223 	dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
224 	if (dm == NULL)
225 		return (NULL);
226 	dnode = &dm->dm_dnode;
227 	dm->dm_mode = 0700;
228 	dm->dm_type = DM_DIR;
229 	if (parent != NULL)
230 		pnode = parent->d_pfs_node;
231 	else
232 		pnode = debugfs_root;
233 
234 	dnode->d_pfs_node = pfs_create_dir(pnode, name, debugfs_attr, NULL, debugfs_destroy, PFS_RD | PFS_NOWAIT);
235 	if (dnode->d_pfs_node == NULL) {
236 		free(dm, M_DFSINT);
237 		return (NULL);
238 	}
239 	dnode->d_pfs_node->pn_data = dm;
240 	return (dnode);
241 }
242 
243 struct dentry *
244 debugfs_create_symlink(const char *name, struct dentry *parent,
245 	const char *dest)
246 {
247 	struct dentry_meta *dm;
248 	struct dentry *dnode;
249 	struct pfs_node *pnode;
250 	void *data;
251 
252 	data = strdup_flags(dest, M_DFSINT, M_NOWAIT);
253 	if (data == NULL)
254 		return (NULL);
255 	dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
256 	if (dm == NULL)
257 		goto fail1;
258 	dnode = &dm->dm_dnode;
259 	dm->dm_mode = 0700;
260 	dm->dm_type = DM_SYMLINK;
261 	dm->dm_data = data;
262 	if (parent != NULL)
263 		pnode = parent->d_pfs_node;
264 	else
265 		pnode = debugfs_root;
266 
267 	dnode->d_pfs_node = pfs_create_link(pnode, name, &debugfs_fill_data, NULL, NULL, NULL, PFS_NOWAIT);
268 	if (dnode->d_pfs_node == NULL)
269 		goto fail;
270 	dnode->d_pfs_node->pn_data = dm;
271 	return (dnode);
272  fail:
273 	free(dm, M_DFSINT);
274  fail1:
275 	free(data, M_DFSINT);
276 	return (NULL);
277 }
278 
279 void
280 debugfs_remove(struct dentry *dnode)
281 {
282 	if (dnode == NULL)
283 		return;
284 
285 	pfs_destroy(dnode->d_pfs_node);
286 }
287 
288 void
289 debugfs_remove_recursive(struct dentry *dnode)
290 {
291 	if (dnode == NULL)
292 		return;
293 
294 	pfs_destroy(dnode->d_pfs_node);
295 }
296 
297 
298 static int
299 debugfs_init(PFS_INIT_ARGS)
300 {
301 
302 	debugfs_root = pi->pi_root;
303 	return (0);
304 }
305 
306 static int
307 debugfs_uninit(PFS_INIT_ARGS)
308 {
309 	return (0);
310 }
311 
312 #ifdef PR_ALLOW_MOUNT_LINSYSFS
313 PSEUDOFS(debugfs, 1, PR_ALLOW_MOUNT_LINSYSFS);
314 #else
315 PSEUDOFS(debugfs, 1, VFCF_JAIL);
316 #endif
317 MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1);
318